This invention relates to an image processing apparatus and an image processing method as well as a recording medium, and more particularly to an image processing apparatus and an image processing method as well as a recording medium by which a network which complies with the standard of the IEEE (Institute of Electrical and Electronics Engineers) 1394 or the like can be used efficiently.
Communication in accordance with the IEEE 1394 standard which is one of standards for a digital interface allows isochronous transfer of data and therefore is suitable for transfer of data which need be played back on the real time basis such as image and sound data. Further, also from an increase in demand for communication of multimedia data in recent years, much attention is paid to the communication in accordance with the IEEE 1394 standard.
FIG. 1 shows a configuration of an example of an AV (Audio Visual) system (the term “system” is used herein to signify a plurality of apparatus gathered logically irrespective of whether or not the apparatus are accommodated in the same housing) which allows communication in accordance with the IEEE 1394 standard.
The AV system of FIG. 1 includes two camcorders (video camcorders) 1 and 2 of the DV (Digital Video) system which are IEEE 1394 apparatus as apparatus which comply with the IEEE 1394 standard, and an IEEE 1394 cable 3. The camcorders 1 and 2 are connected to each other by the IEEE 1394 cable 3.
It is to be noted that, in the following description, in order to avoid complicated description, description is given only of image data from between image data and sound data. Further, in the following description, it is assumed that image and sound data played back by the camcorder 1 are transmitted by the IEEE 1394 cable 3 to and outputted from the camcorder 2.
FIG. 2 shows an example of configuration of the camcorders 1 and 2 of FIG. 1.
The camcorder 1 includes a mechanism deck 11, a signal processing circuit 12, an interface circuit 13, a display 14, a control circuit 15, and an operation panel 16.
The mechanism deck 11 records image data supplied thereto from the signal processing circuit 12 onto a video tape not shown, and plays back image data from the video tape and supplies the played back image data to the signal processing circuit 12.
The signal processing circuit 12 performs necessary signal processing for image data supplied thereto from the interface circuit 13 and supplies the processed image data to the mechanism deck 11. Further, the signal processing circuit 12 performs necessary signal processing for image data supplied thereto from the mechanism deck 11 and supplies the processed image data to the interface circuit 13 and the display 14.
The interface circuit 13 functions as an interface for allowing communication compliant with the IEEE 1394 standard. In particular, the interface circuit 13 converts the format of image data and other data supplied thereto from the signal processing circuit 12 into that of data compliant with the IEEE 1394 standard and transmits the resulting data to the IEEE 1394 cable 3. Further, the interface circuit 13 receives image data and other data from the IEEE 1394 cable 3, converts the format of the received data back into its original format and supplies the data of the original format to the signal processing circuit 12.
The display 14 is formed from, for example, a CRT (Cathode Ray Tube) or a liquid crystal panel and displays image data from the signal processing circuit 12.
The control circuit 15 controls the mechanism deck 11, signal processing circuit 12, interface circuit 13 and display 14 in response to an operation signal from the operation panel 16 and so forth.
The operation panel 16 includes buttons and so forth to be operated in order to input various instructions such as playback of image data, pause or fast feeding, and supplies an operation signal corresponding to an operated button to the control circuit 15. It is to be noted that the operation panel 16 may otherwise be a panel provided integrally on the camcorder 1 or a remote commander for remotely controlling the camcorder 1.
The camcorder 2 includes a mechanism deck 21, a signal processing circuit 22, an interface circuit 23, a display 24, a control circuit 25 and an operation panel 26 which have configurations similar to those of the mechanism deck 11, signal processing circuit 12, interface circuit 13, display 14, control circuit 15 and operation panel 16 of the camcorder 1, respectively.
Now, operation of the AV system of FIG. 2 is described.
First, for example, in order to cause the camcorder 1 to record image data, the user will connect an image inputting apparatus (not shown) which can input an image such as a video camera to the interface circuit 13 using the IEEE 1394 cable 3, and operate the button (recording button) of the operation panel 16 for inputting a recording instruction. In this instance, the operation panel 16 supplies an operation signal for a recording instruction to the control circuit 15. When the control circuit 15 receives the operation signal for a recording instruction, it sets the operation mode of the apparatus to a recording mode.
Thereafter, when image data are inputted from the image inputting apparatus to the interface circuit 13 through the IEEE 1394 cable 3, the interface circuit 13 receives the image data and supplies the image data to the signal processing circuit 12.
The signal processing circuit 12 performs predetermined signal processing for the image data from the interface circuit 13 and supplies the processed image data to the mechanism deck 11. The mechanism deck 11 records the image data from the signal processing circuit 12 onto the video tape.
On the other hand, in order to play back image data recorded by the camcorder 1 and transmit the image data to the camcorder 2 so that the image data are displayed by the camcorder 2, the user will operate the button (playback button) of the operation panel 16 for inputting a playback (normal playback) instruction. In this instance, the operation panel 16 supplies an operation signal for a playback instruction to the control circuit 15. The control circuit 15 receives the operation signal for a playback instruction and sets the operation mode of the apparatus to a playback mode.
After the playback mode is entered, the mechanism deck 11 starts playback of image data from the video tape and supplies the played back image data to the signal processing circuit 12. The signal processing circuit 12 performs predetermined signal processing for the image data from the mechanism deck 11, and supplies image data of, for example, the NTSC (National Television System Committee) system to the interface circuit 13 and supplies the image data to the display 14 so as to be displayed on the display 14. The interface circuit 13 transmits the image data from the signal processing circuit 12 to the camcorder 2 through the IEEE 1394 cable 3.
The image data transmitted from the camcorder 1 through the IEEE 1394 cable 3 in such a manner as described above are received by the interface circuit 23 of the camcorder 2. After the interface circuit 23 starts reception of the image data, it notifies the control circuit 25 that image data are inputted thereto. In this instance, the control circuit 25 sets the operation mode of the apparatus to an input mode.
After the input mode is entered, the interface circuit 23 supplies the image data received from the IEEE 1394 cable 3 to the signal processing circuit 22. The signal processing circuit 22 supplies the image data from the interface circuit 23 to the display 24 so that the image data are displayed on the display 24.
Then, if the user thereafter operates the button (recording button) of the operation panel 26 for inputting a recording instruction, then the operation panel 26 supplies an operation signal for a recording instruction to the control circuit 25. In this instance, the control circuit 25 sets the operation mode of the apparatus to a recording mode. After the recording mode is entered, the signal processing circuit 22 supplies the image data from the interface circuit 23 not only to the display 24 but also to the mechanism deck 21. The mechanism deck 21 records the image data supplied thereto from the signal processing circuit 22 in such a manner as described above onto the video tape.
Here, if the power supply to the camcorder 1 and the camcorder 2 is placed into an on state, then the interface circuit 13 of the camcorder 1 and the interface circuit 23 of the camcorder 2 recognize IEEE 1394 apparatus connected thereto by the IEEE 1394 cable 3 (in FIG. 2, the camcorders 1 and 2) and establish a cannel (logical channel) for use for delivery of image data. Then, between the camcorders 1 and 2, data are communicated through the channel. It is to be noted that detailed description of establishment of a channel in the IEEE 1394 is omitted herein.
Then, if the user operates, for example, the button (fast feed button) of the operation panel 16 for inputting a fast feed (Fast Forward) instruction, then the operation panel 16 supplies an operation signal for a fast feed instruction to the control circuit 15. In this instance, the control circuit 15 sets the operation mode of the apparatus to a fast feed mode.
After the fast feed mode is entered, the mechanism deck 11 feeds the video tape at a speed equal to several times that for playback at a normal speed (normal playback) to play back image data intermittently and supplies the played back image data to the signal processing circuit 12. The signal processing circuit 12 processes the intermittent image data from the mechanism deck 11 to produce normal image data of the NTSC system and supplies the image data to the interface circuit 13 and also to the display 14 so that the image data are displayed on the display 14. The interface circuit 13 sends the image data from the signal processing circuit 12 to the camcorder 2 through the IEEE 1394 cable 3.
The camcorder 2 controls the display 24 to display the image data from the camcorder 1 in a similar manner to that in the normal playback described hereinabove. It is to be noted that, while the image data transmitted thereto from the camcorder 1 in this instance are of the NTSC system, they are data of frames at intervals of several frames, and therefore, moving pictures in a fast fed state are displayed on the display 24.
Then, if the user operates, for example, the button (pause button) of the operation panel 16 for inputting a pause (temporarily stop) instruction, then the operation panel 16 supplies an operation signal for a pause instruction to the control circuit 15. In this instance, the control circuit 15 sets the operation mode of the apparatus to a pause mode.
After the pause mode is entered, the mechanism deck 11 stops feeding of the video tape and supplies image data of the same frame obtained by repetitively scanning the same portion of the video tape to the signal processing circuit 12. The signal processing circuit 12 processes the video data from the mechanism deck 11 to produce normal image data of the NTSC system and supplies the image data to the interface circuit 13 and also to the display 14 so that the image data are displayed on the display 14. The interface circuit 13 transmits the image data from the signal processing circuit 12 to the camcorder 2 through the IEEE 1394 cable 3.
The camcorder 2 controls the display 24 to display the image data from the camcorder 1 in a similar manner as in the normal playback. It is to be noted that, while the image data transmitted from the camcorder 1 are of the NTSC system, since they are of the same frame, moving pictures of a pause state are displayed on the display 24.
FIG. 3 shows another configuration of example of the AV system.
The AV system of FIG. 3 includes a hard disk recorder 31 and a digital television monitor 32 of the DV (Digital Video) system which are IEEE 1394 apparatus as apparatus which comply with the IEEE 1394 standard, and an IEEE 1394 cable 3. The hard disk recorder 31 and the digital television monitor 32 are connected to each other by the IEEE 1394 cable 3.
It is to be noted that, in the following description, it is assumed basically that an image played back by the hard disk recorder 31 is transmitted through the IEEE 1394 cable 3 to the digital television monitor 32 by which it is outputted (displayed).
The hard disk recorder 31 includes a hard disk 41, a signal processing circuit 42, an interface circuit 43, a control circuit 44 and an operation panel 45. The signal processing circuit 42, interface circuit 43, control circuit 44 and operation panel 45 are similar to the signal processing circuit 12, interface circuit 13, control circuit 15 and operation panel 16 of FIG. 2, respectively. Accordingly, the hard disk recorder 31 is configured basically similarly to the camcorder 1 of FIG. 2 except that it does not include the display 14 and includes the hard disk 41 in place of the mechanism deck 11.
The digital television monitor 32 includes a interface circuit 51, a signal processing circuit 52, an display 53 and a control circuit 54. The interface circuit 51, signal processing circuit 52, display 53 and control circuit 54 are similar to the interface circuit 23, signal processing circuit 22, display 24 and control circuit 25 of FIG. 2, respectively. Accordingly, the digital television monitor 32 is configured basically similarly to the camcorder 2 of FIG. 2 except that it does not include the mechanism deck 21 or the operation panel 26.
Now, operation of the AV system of FIG. 3 is described.
Also in the AV system of FIG. 3, similarly as in the AV system of FIG. 3, if the power supply to the hard disk recorder 31 and the digital television monitor 32 is placed into an on state, then the interface circuit 43 of the hard disk recorder 31 and the interface circuit 51 of the digital television monitor 32 recognize IEEE 1394 apparatus connected thereto by the IEEE 1394 cable 3 (in FIG. 3, the hard disk recorder 31 and the digital television monitor 32) and establish a cannel (logical channel) for use for delivery of data. Then, between the hard disk recorder 31 and the digital television monitor 32, data are delivered through the channel.
First, for example, in order to cause the hard disk recorder 31 to record image data, the user will connect an image inputting apparatus (not shown) which can input an image such as a video camera to the interface circuit 43 using the IEEE 1394 cable 3, and operate the button (recording button) of the operation panel 45 for inputting a recording instruction. In this instance, the operation panel 45 supplies an operation signal for a recording instruction to the control circuit 44. When the control circuit 44 receives the operation signal for a recording instruction, it sets the operation mode of the apparatus to a recording mode.
Thereafter, when image data are inputted from the image inputting apparatus to the interface circuit 43 through the IEEE 1394 cable 3, the interface circuit 43 receives the image data and supplies the image data to the signal processing circuit 42.
The signal processing circuit 42 performs necessary signal processing for the image data from the interface circuit 43 such as, for example, conversion into image data of the DV system and supplies the resulting image data to the hard disk 41 so as to be recorded onto the hard disk 41.
On the other hand, in order to play back image data recorded by the hard disk recorder 31 and transmit the image data to the digital television monitor 32 so that the image data are displayed, the user will operate the button (playback button) of the operation panel 45 for inputting a playback (normal playback) instruction. In this instance, the operation panel 45 supplies an operation signal for a playback instruction to the control circuit 44. The control circuit 44 receives the operation signal for a playback instruction and sets the operation mode of the apparatus to a playback mode.
After the playback mode is entered, the signal processing circuit 42 starts playback of image data from the hard disk 41. It is to be noted that, if the user operates the operation panel 45 to designate image data (contents) to be played back, then the signal processing circuit 42 starts playback of the image data designated by the user beginning with the top of the image data. On the other hand, for example, if the user does not particularly designate image data to be played back, then the signal processing circuit 42 starts playback from a position of the hard disk 41 determined in advance (for example, from a position at which the last playback ended).
The signal processing circuit 42 decodes the image data played back from the hard disk 41 and outputs the decoded image data from an output terminal not shown. In particular, since image data of the DV system are recorded on the hard disk 41, the signal processing circuit 42 decodes the image data of the DV system into image data of, for example, the NTSC system and outputs the decoded image data from the output terminal.
The signal processing circuit 42 supplies the image data of the DV system played back from the hard disk 41 to the interface circuit 43. The interface circuit 43 transmits the image data of the DV system from the signal processing circuit 42 to the digital television monitor 32 through the IEEE 1394 cable 3.
Accordingly, here, image data compression coded in accordance with the DV system are transmitted from the hard disk recorder 31 to the digital television monitor 32 through the IEEE 1394 cable 3. It is to be noted that, although it is possible to transmit image data of the NTSC system or the like obtained by decoding image data of the DV system from the hard disk recorder 31 to the digital television monitor 32, between different IEEE 1394 apparatus, image data of the DV system are usually communicated as they are.
The image data transmitted from the hard disk recorder 31 through the IEEE 1394 cable 3 in such a manner as described above are received by the interface circuit 51 of the digital television monitor 32. The interface circuit 51 supplies the image data to the signal processing circuit 52. The signal processing circuit 52 decodes the image data of the DV system from the interface circuit 51 into image data of, for example, the NTSC system and supplies the resulting image data to the display 53 so that the image data are displayed on the display 53.
Then, if the user operates, for example, the button (fast feed button) of the operation panel 45 for inputting an instruction for fast feeding, then the operation panel 45 supplies an operation signal for a fast feed instruction to the control circuit 44. In this instance, the control circuit 44 sets the operation mode of the apparatus to a fast feed mode.
After the fast feed mode is entered, the signal processing circuit 42 plays back the image data for each N frames.
While image data compression coded in accordance with the DV system are recorded on the hard disk 41, the data amount per one frame in the DV system is known and the data of the DV system include only intra-coded images without involving interframe coding, it is possible to play back image data of the DV system for each plurality of frames. It is to be noted that it is otherwise possible to record image data compression coded in accordance with a system which involves interframe coding such as, for example, the MPEG system on the hard disk 41. In this instance, for detection of image data of a predetermined frame, a method disclosed in Japanese Patent Laid-Open No. Hei 6-325553 or No. Hei 11-312381 filed for patent in Japan by the assignee of the present application can be adopted.
If the signal processing circuit 42 plays back image data after each N−1 frames from the hard disk 41, then N-fold speed playback is performed.
The signal processing circuit 42 supplies the image data played back from the hard disk 41 to the interface circuit 43. The image data are thereafter transmitted to the digital television monitor 32 in a similar manner to that in the normal playback.
The digital television monitor 32 controls the display 53 to display the image data from the hard disk recorder 31 in a similar manner to that in the normal playback described hereinabove. It is to be noted that, since the image data transmitted thereto from the hard disk recorder 31 in this instance are data of frames at intervals of N frames, moving pictures in a fast fed state are displayed on the display 53.
Then, if the user operates, for example, the button (pause button) of the operation panel 45 for inputting a pause instruction, then the operation panel 45 supplies an operation signal for a pause instruction to the control circuit 44. In this instance, the control circuit 44 sets the operation mode of the apparatus to a pause mode.
After the pause mode is entered, the signal processing circuit 42 supplies image data of the same frame obtained by repetitively playing back a frame of the image data, which has been played back last from the hard disk 41, from the hard disk 41 to the interface circuit 43. The interface circuit 43 transmits the image data from the signal processing circuit 42 to the digital television monitor 32 and also to the display 14 so that the image data are displayed through the IEEE 1394 cable 3.
The digital television monitor 32 controls the display 53 to display the image data from the hard disk recorder 31 in a similar manner as in the normal playback. In this instance, the image data transmitted from the hard disk recorder 31 are data of the same frame as described above, and therefore, moving pictures of a pause state are displayed on the display 53.
As described above, in the AV systems described above, even if a pause instruction is issued, image data of the same frame are transmitted repetitively through the IEEE 1394 cable 3. In other words, also when a pause mode is established, image data are transmitted occupying a transmission bandwidth similar to that in normal playback. More particularly, where the image data to be transmitted are data, for example, of the NTSC system, they are transmitted occupying a transmission bandwidth corresponding to 29.97 frames/sec.
Accordingly, although there is no problem if the communication through the IEEE 1394 cable 3 is used only for transmission of the image data, if it is used also for delivery of data by another application, a limited transmission bandwidth is used by transmission of image data of the same frame and the delivery of data by another application is limited. Thus, the transmission bandwidth is not utilized efficiently.